The present invention generally relates to electric drive systems and more particularly to methods and apparatus for providing thermal protection for such systems.
A high-power electric drive system contains many components that are subject to substantial amounts of heat load. All these components may have their own thermal designs for heat rejection and are usually equipped with temperature sensors for protection from over-temperature. Typical operation of the system is to allow full performance until a component exceeds a safe temperature limit, and then the whole system will shut down. A system controller may restart the system after the component temperature cools down. However, during shutdown, the system is not available for operation. For some applications, this is not a desirable or even acceptable condition. The issue can be more complicated when the components of the system are installed in different environments.
As can be seen, there is a need for a thermal protection system that may allow a drive system to continue operation during periods when the temperature of one or more of its components approaches a predetermined safe limit.